基于CPTU测试的高速公路扩建地基软土参数空间变异性研究  

Study on Spatial Variability of Soft Soil Parameters for Expressway Expansion Foundation Based on Piezocone Penetration Testing

作　　者：王才进 武猛 杨洋 何欢 蔡国军[1,3] 刘薛宁 刘松玉 WANG Cai-jin;WU Meng;YANG Yang;HE Huan;CAI Guo-jun;LIU Xue-ning;LIU Song-yu(Institute of Geotechnical Engineering,Southeast University,Nanjing 211189,Jiangsu,China;Jiangsu Province Transportation Engineering Construction Bureau,Nanjing 210o04,Jiangsu,China;School of Civil Engineering,Anhui Jianzhu University,Hefei 230601,Anhui,China)

机构地区：[1]东南大学岩土工程研究所,江苏南京211189 [2]江苏省交通工程建设局,江苏南京210004 [3]安徽建筑大学土木工程学院,安徽合肥230601

出　　处：《中国公路学报》2024年第2期197-208,共12页China Journal of Highway and Transport

基　　金：国家杰出青年科学基金项目(42225206);国家自然科学基金项目(41877231);江苏省交通运输科技项目(7921004042B)。

摘　　要：为研究改扩建工程新老路地基软土的空间变异性,对连云港—淮安(连淮)高速公路扩建工程的新老路地基进行孔压静力触探(CPTU)测试,使用地质统计学对区域范围内的锥尖阻力进行插值预测,对插值结果进行独立验证,使用插值结果对新老路地基软土的超固结比(OCR)、不排水抗剪强度Su和压缩模量Es进行计算分析,并对新老路地基的沉降进行计算。研究结果表明:所建立的地质统计学模型能够准确预测新老路地基土体的锥尖阻力,其独立验证结果的相关系数R2大于0.87;新老路地基表层土体的OCR较大,老路地基土体的OCR明显大于新路地基;Su主要分布在0~300 kPa,总体随深度的增加而增加,局部能达到300 kPa以上;Es主要分布在0~20 MPa,Es随深度的增加而增大,整体上老路地基的Es大于新路地基;新老路地基的沉降主要集中在深度0~7 m,新老路地基的差异沉降较大,最大能达到1 130 mm。使用地质统计学基于有限的勘察资料对区域范围内的新老路地基软土的工程特性进行分析研究,对改扩建工程的设计具有重要意义。In this study,piezocone penetration testing was used to study the spatial variability of the soft soil on the new and old road foundations of the Lianyungang Huai'an Expressway reconstruction and expansion project.Geostatistics were used to interpolate and predict the cone tip resistance within the region and to independently verify the interpolation results.The interpolation results were used to analyze the over consolidation ratio(OCR),undrained shear strength(S_u),and compressive modulus(E_s)of the soft soil on the new and old road foundations and to calculate their settlements.The research results show that the established geostatistical model can accurately predict the cone tip resistance of the foundation soils of new and old roads.The correlation coefficient(R~2)of its independent verification results exceeds 0.87.The OCRs of the surface soils of the new and old road foundation are relatively large;the OCR of the old road foundation soil is significantly greater than that of the new road foundation soil.The S_u is mainly distributed in the range of 0 to 300 kPa and generally increases with depth.It can reach over 300 kPa locally.The E_s is mainly distributed in the range of 0 to 20 MPa and also increases with depth.On the whole,the E_s of the old road foundation is greater than that of the new road foundation.The settlements of the foundations of the new and old roads are mainly concentrated in the depth range of 0 to 7 m.The differential settlement of the foundations of the new and old roads is relatively large,with a maximum of 1130 mm.This approach,i.e.,using geostatistics based on limited survey data to analyze and study the engineering characteristics of the soft soils on the foundations of new and old roads within the region,shows great significance for the design of reconstruction and expansion projects.

关 键 词：路基工程 软土 CPTU测试 改扩建工程 地质统计学 沉降计算 

分 类 号：U413[交通运输工程—道路与铁道工程]